Note: Descriptions are shown in the official language in which they were submitted.
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Interchangeable Tips for Medical Laser Treatments and Methods for Using Same
Inventors: Len DeBenedictis; John Black; Robert Kehl Sink; Kin F. Chan; Tom
Myers; George
Frangineas; Wayne Stuart; Jeff Sobiech
RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. 119(e) to U.S.
Provisional Patent
Application Serial No. 60/609,037, "Interchangeable Tips for Medical Laser
Treatments and
Methods for Using Same," filed Sept. 9, 2004 by Len DeBenedictis et al. The
subject matter of the
forcgoing is incoiporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods and apparatus for
providing medical or
surgical treatment using optical energy, and in pai-ticular to interchangeable
tips coupled to a
handpiece in a treatment system and a method for using such tips for treatment
of tissue (e.g.,
human skin) using optical radiation.
BACKGROUND OF THE INVENTION
[0003] Lasers and other intense light sources are used for various types of
tissue treatment,
including dermatological tissue treatment. Optical energy, particularly laser
energy, is commonly
used as a versatile tool in medicine to achieve desired outcomes in the tissue
that is treated. For
example, lasers have been used to treat common dermatological problems such as
hypervascular
lesions, pigmented lesions, acne scars, rosacea, hair removal, etc.
Additionally, lasers are also used
in aesthetic surgery for achieving better cosmetic appearance by resurfacing
the skin and
remodeling the different layers of skin to improve the appearance of wrinkled
or aged skin.
Generally, skin resurfacing is understood to be the process by which the top
layers of the skin are
completely removed by using chemicals, mechanical abrasion or lasers to
promote the development
of new, more youthful looking skin and stimulate the generation and growth of
new skin. In laser
skin remodeling, laser energy penetrates into the deeper layers of the skin
and is aimed at
stimulating the generation of and/or altering the structure of extra-cellular
matrix materials, such as
collagen, that contribute to the youthful appearance to skin.
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[00041 During deiniatological tissue treatment utilizing light, a light beam
irradiates the skin
surface of a patient. Generally, lasers that are used for such treatment
operate at a wavelength that
is absorbed by one of the natural chromophores in the skin, such as water,
although chromophores
may also be added to the tissue. In the case of water as the primary
chromophore, cellular and
interstitial water absorbs light energy and transforms the light energy into
theimal energy. The
transpoi-t of thermal energy in tissues during treatment is a complex process
involving conduction,
convection, radiation, metabolism, evaporation and phase change that vary with
the operational
parameters of the light beam. It is impoi-tant in such procedures not to
damage tissue underlying or
surrounding the target tissue area. If the light beam optical operational
parameters, such as
wavelength, power, the intensity of the light, pulse duration, rate of
emission, etc. are properly
selected, cellular and interstitial water in the patient's skin is heated
causing temperature increases
that produce a desired deimatological effect. Conversely, improper selection
of the optical
operational parameters can result in undertreatment or overtreatment of the
tissue. Therefore, it is
desirable to accurately control optical operational parameters used in the
treatment so that the light
is delivered to the tissue with the proper fluence and in a unifoim,
controllable manner.
[0005] Devices for dermatological tissue treatment include a hand-held
delivery apparatus,
sometimes referred to as a handpiece. A handpiece is a prefei7=ed means by
which physicians apply
treatment to tissue. During treatment, the handpiece emitting light is moved
by a physician's hand
along the tissue to be treated. Treatment level from such a device is
typically set in advance by
manually selecting the light beam operational parameters. The operational
parameters, which for
example include power level, energy, pulsation rate, temperature, light
intensity, and cuiTent,
determine the degree of treatment of the entire treatment process.
[0006] A typical approach of conventional handpieces is to produce a
macroscopic, pulsed
treatment beam that is manually moved from one area of the skin to another in
a patchwork like
manner in order to treat a larger region of skin tissue. Such an approach has
the disadvantage of
producing artifacts and sharp boundaries associated with the inaccurate
positioning of the
individual treatments with respect to the treated skin surface.
[0007] Another disadvantage of conventional handpieces is that, as discussed
above, the laser
operational parameters defining the selected level of treatment are typically
pre-set once for the
entire course of treatment. The individual tissue properties of each patient
are factored in based on
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a preliminary tissue assessment prior to the treatment and the treatment can
proceed using the
predetermined operational parameters.
[0008] For example, some handpiece apparatuses may provide feedback indicating
to the physician
the rate of the handpiece movement which allows the physician to adjust the
treatment speed. But
this handpiece apparatus requires the physician to treat at a pre-selected
rate of motion. The
disadvantage of this apparatus is that it restricts the physician to a single
treatment speed. In large
flat areas, such as the cheek, it is desirable to treat at a high speed. In
highly contoured areas, such
as the lip, it is desirable to treat at a lower speed. Restricting the
physician to a pre-selected rate of
motion limits the flexibility of the physician when treating regions, such as
the face, that include
both large flat areas and highly contoured areas that are in close proximity.
Additionally, if the
speed of the handpiece changes during the treatment procedure, the apparatus
does not provide for
automatic adjustment of its operational parameters to compensate for the
changed rate of
movement, leading to uneven treatment.
[0009] The application of robotic means used in the field of dermatological or
cosmetic surgery
could overcome the limitation of human imprecision. However, one disadvantage
of typical
conventional robotic apparatuses is that they lack the necessaiy direction and
judgment in treatment
that a physician provides. Although robotics is precise, it is not typically
intelligent enough to
make complex choices or react to unforeseen circumstances during treatment.
Additionally, robots
deprive a physician of discretion in an aesthetic sense. Another disadvantage
of the typical
conventional robotic apparatus is that the full treatment may require complete
inunobilization of the
patient. Alternatively, a sophisticated image stabilization system must be
employed to compensate
for patient's movement.
[0010] Many current medical laser systems are used in contact with tissue
being treated. Such
contact systems require cleaning and special care to maintain cleanliness, if
not sterility depending
on the treatment, as well as efficacy. Such contact systems often include a
window or some
aperture through which energy passes. If such windows or apertures become
blocked - such as by
foreign substances, scratches, chips, or cracks - then the device typically
will not function properly.
Conventional systems typically have a monolithic handpiece with unchangeable
mechanical,
electrical and optical components, configurations and connections.
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[0011] The present invention provides apparatuses and methods which
significantly reduce the
problems associated with the existing medical laser systems and methods.
SUMMARY OF THE INVENTION
[0012] In general, the present invention features an interchangeable tip for a
medical treatment
system. A typical treatment system for use with tip embodiments includes an
electromagnetic
energy source, such as, for example, a laser or radio frequency generator. A
set of tips may be
interchangeably attached to the treatment system, for example to alter the
system parameters and
the treatment provided through the individual tips. Enlbodiments of the
present invention include
tips with an attached security chip and/or a memory. A security chip protects
the treatment system
from use with unauthorized tips, and the memoiy stores infoimation about the
tips and/or the
treatment system to enhance the treatment. The tips may be authenticated
through the use of a
keyed hash algorithm, such as, for example, the SHA- 1 algorithm. The
authentication may occur
through a comnzunications device, such as an electrical connector or wireless
connection, attached
to the tip.
[0013] Embodiments of the present invention feature a removable tip apparatus
for use with a
medical light energy treatment system that includes a handpiece. The tip
apparatus includes a
housing, a light energy pathway and a security chip. The housing is shaped so
that the tip can be
removably attached to the distal end of the handpiece. When the tip is
attached, the light energy
pathway provides a path for transmitting light energy from the distal end of
the handpiece through
the tip apparatus to a target area. The security chip is used to determine
whether or not to enable
delivery of light energy to the distal end of the handpiece. For example, if
the security chip is
invalid or missing, then light energy may be disabled. If the security chip is
valid, indicating that
the tip is authentic, then the light energy may be transmitted.
[0014] In another aspect of the present invention, a medical light energy
treatment system includes
a light source, a handpiece and a set of two or more different but
interchangeable tips. The
handpiece is optically coupled to the light source and is configured to
transmit light energy fi=om
the light source to a distal end of the handpiece. The tips can be removably
attached to the distal
end of the handpiece. When attached, each tip transmits at least a portion of
the light energy from
the distal end of the handpiece through the tip to a target area. However, the
tips are different. For
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example, the tips may have different configurations, different physical
designs or dimensions
and/or different operating characteristics. The differences operate to cause
different treatments.
[0015] In a further embodiment, a medical light energy treatment system
includes a light source,
handpiece, interchangeable tips and a host processor. The light source,
handpiece and tips operate
similarly as above. However, the tips also include attached memory that stores
tip-specific data, for
example system usage time for the tip, energy ti=ansmitted thi=ough the tip,
energy pulse count data
for the tip, tip type, tip configuration and/or tip parameters. The host
processor, which is located
external to the tips, communicates with the memory to access the tip-specific
data as part of the
treatment process.
[0016] Other aspects of the invention include methods, systems and
applications relating to the
embodiments described above
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features , objects and advantages of the present
invention are more readily
understood from the following detailed description in conjunction with the
accoinpanying
drawings, where:
[0018] FIG. I is an illustration of a medical treatment system including a
handpiece.
[0019] FIG. 2 is a diagrammatic view of an apparatus showing feedback control
of the laser power
for controlled tissue treatment.
[0020] FIG. 3 is a side view of a handpiece including a detector and an
optical element.
[0021] FIG. 4 shows a detector of the handpiece shown in FIG. 3 in sensing
mode in greater detail
[0022] FIG. 5 shows a tip according to one embodiment of the present
invention.
[0023] FIG. 6 shows a tip according to an alternate embodiment of the present
invention.
[0024] FIG. 7 illustrates various dimensions and configurations of a tip
according to embodiments
of the present invention.
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[00251 FIGS. Sa and 8b illustrate embodiments of the present invention with
different tip
dimensions and the impact of such difference on treatment parameters.
DETAILED DESCRIPTION
[00261 Much of the discussion and many of the embodiments discussed herein
relate to
dermatology applications. However, this should not be viewed as limiting the
inventions herein
solely to deimatology. Generally, treatment of biological tissues by
electromagnetic energy
through interchangeable tips is included in the present invention. While the
embodiments will
focus on the use of optical energy, the scope of the invention is intended to
extend to
electromagnetic energy such as radio frequency or microwave treatment devices
as well. PrefeiTed
radio-frequeney and microwave treatment devices will have an electromagnetic
frequency within
the range of 300 kHz to 3 GHz and more preferably within the range of 4 MHz to
10 MHz. The
electromagnetic frequency can be chosen based on the desired depth of
penetration of the energy.
[0027] Embodiments of the present invention include tips that are
interchangeable and may be
disposable. Additional benefits include the ability to change treatment system
parameters and
treatment parameters by changing tips, which is typically much simpler and
more efficient than
changing optical elements or the mechanical configuration of the handpiece
itself. For example,
different tips may have different dimensions along the optical axis of the tip
in order to alter the
focal depth of the treatment beam into the tissue and/or the spot size of the
treatment beam at the
tissue surface. Different tips may have different sizes in dimensions other
than those parallel to the
optical axis of the treatment beam. Different tips may also have different
shapes, some of which
may be sized and shaped to treat specific conditions or specific anatomical
structures, for example.
Different tips may have different filter properties in order to limit the
wavelength(s) of the light
transnlitted through the tip. Further alternate embodiments may include
different LEDs for various
tracking or sensing purposes, as well as vaiying the location of the LED or
the window through
which the LED light is transmitted to the tissue surface. By keeping the
optical system, laser
system and handpiece mechanics in a relatively constant configuration in the
handpiece and
changing tips, cost and complexity is reduced while providing a variety of
effective treatment
parameters from a single handpiece.
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[0028] Further embodiments of the present invention include interactions
between the tips and the
medical laser system to which the tip is attached. Embodiments of the present
invention will
typically include tips that have an attached security chip and/or a memory.
The memory will often
be part of a security chip, although separate or additional memoiy may also be
included. The
memory may hold various codes and/or data. For example, an encrypted security
code may be
included to ensure that only approved and/or specified tips are used with a
given medical laser
system. Additionally, inforniation relating to the usage of the tip or the
system may be stored in the
memory. For example, such tip usage data may include: accumulated time of use;
clock time since
the tip was attached to the medical laser system or the medical laser system
was first turned on with
the tip attached; number of pulses transmitted through the tip; accumulated
energy or fluence
transmitted through the tip; accumulated power transmitted through the tip;
number of patients
treated using the tip; number of treatment spots laid down through the tip;
etc. Further alternate
embodiments may include storing tip andlor treatment system information in the
memory. For
example, the tip type may be stored in the memoiy so that the treatment system
controller or
processor can read the tip type and set system operating parameters
accordingly. For example, the
tip type information may include tip dimensions such as the dimension along
the optical axis of the
tip so that the treatment system can calculate the spot size at the tissue
surface and/or the focal
depth of a treatment beam in the tissue. Using these calculations, the
treatment system may, for
exaniple, limit the maximum energy applied per pulse in order to control
damage to the tissue.
Alternately, tip information may include the dimensions of the treatment area
for the tip, and the
system may then alert the system user to these dimensions and the resultant
impact on the treatment
regimen to be used with that tip. Individual tips in a set or plurality of
tips configured to be
attached to a single system or handpiece may be designed for specific purposes
such as, for
example: treatment of wrinkles, scars, pigmented lesions, hair removal or
growth; drug delivery;
treatments around eyes, neck, nose; targeting of anatomical stiuctures, such
as veins or lesions; etc.
A user interface attached to the treatment system allows a user to obtain
information relating to the
tip as well as information relating to a given tip's iunpact on the treatment
system configuration and
treatment parameters. A user may then alter treatment parameters and/or switch
tips to achieve the
desired treatment.
[0029] Embodiments of improved laser treatment systems and methods employing
robotics and
motion control feedback are found at co-pending U.S. Patent Applications No.
10/745,761 and
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60/605,092 (Attorney docket number 23920-09449) each assigned to Reliant
Technologies, Inc.,
and entitled "Method And Apparatus For Monitoring And Controlling Laser-
Induced Tissue
Treatment", filed on December 23, 2003, and August 26, 2004, respectively, and
both incorporated
herein by reference in their entireties. These embodiments typically use a
light-emitting diode
(LED) or some other illumination source to illuminate the tissue so that it
may be more easily
detected. Further, co-pending U.S. Application No. 10/367,582, entitled
"Method And Apparatus
For Treating Skin Using Patterns Of Optical Energy", filed on February 14,
2003, and co-pending
U.S. Application No. 10/888,356 (Attorney docket number 23920-09289), entitled
"Method And
Apparatus For Fractional Photo Therapy Of Skin", filed on July 9, 2004, each
assigned to Reliant
Technologies, Inc., describe the use of fractional laser therapy and the value
of discrete microscopic
treatment zones with untreated tissue left between such zones, both of which
applications are
incorporated herein by reference in their entireties.
100301 In laser treatments including those using microscopic spots (i.e.
typically less than about
500 microns in diameter, and preferably less than about 200 microns, typically
measured at the
largest necrotic zone lesion dimension perpendicular to the optical axis of
the treatment beam),
various parameters are important to producing the desired and effective
treatment results. For
example, important parameters may include one or more of the following: the
wavelength of the
light transmitted to the tissue; the size of the treatment spot at the tissue
surface; the focal depth of
the treatment beam, typically measured from the tissue surface or the surface
of the contact surface
of the handpiece; the amount of heating or cooling at the tissue surface; and
the configuration of the
exit window or aperture for the treatment handpiece (e.g., contact or non-
contact windows, window
or aperture shape), etc. Embodiments of the present invention include tips
that enhance the
effectiveness of the inventions and embodiments described in the above-
referenced co-pending
patent applications. However, tip embodiments described herein are not limited
solely to use in
conjunction with the afore-mentioned patent applications or the inventions
described therein.
[0031] Treatment systems that use microscopic spot sizes or focus to depths of
less than 4 mm into
the skin typically use higher treatnient fluences of optical energy than
systems with larger spot
sizes. The higher fluences can cause damage to the tip window and cause
significant scattering,
which is also more significant for microscopic spot sizes and may cause
undertreatment or
inconsistent treatment. Therefore, it is desirable to have an apparatus for
storing tip usage data
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securely so that the system can verify that tips are replaced after a defined
amount of usage. The
tip usage data can be stored securely on the tip in the memory using the
encryption algorithnis
described herein.
[0032] FIG. 1 shows the basic elements of a typical medical treatment system.
In this treatment
system, a handpiece 102 is coupled to a console 122 via a cable 112. Console
122 may not be
included in all embodiments, in which case laser system(s) and controllers may
be free-standing
and separate with various electrical and optical connections there between. A
handpiece is
typically maneuverable and sized for manipulation by human hand. Cable 112
typically carries and
protects various optical fibers and electrical wires. The console 122
typically holds one or more
light systems, such as, for example, a laser system 106. The optical fibers in
cable 112 are optically
coupled to the one or more light systems and the handpiece 102 in order to
transmit the light energy
fi=om the light system(s) to the handpiece. A user input/output (UO) interface
124 is typically
included in or attached to the treatment system so that a user may interact
with, control and receive
information from the treatment system.
[0033] FIG. I shows an example of a handpiece 102 connected to two laser
systems 106 and 108.
In the example shown in FIG. 1, laser systems are depicted as the light
systems. However, one
skilled in the art will recognize that a non-laser light source, such as
flashlamps or LEDs, may be
used in place of a laser. A second laser system 108 may be coupled to the
handpiece 102. Optical
pathways in cables 112 and/or 114 are typically used to transmit light from
the laser system(s) 106
and/or 108 to the handpiece 102. Laser systems 106, 108 typically include a
control system 116,
118 for the laser; the control system may be intemal or external, and may be
shared between lasers.
The control system typically includes a controller, microprocessor and/or
digital signal processor
(DSP) along with software or firmware for use in controlling operational
characteristics of the laser,
such as, for example, pulse length, energy, wavelength (for tunable lasers),
duty cycle, and so forth.
One skilled in the art will recognize that two laser systems 106 and 108 may
transmit light through
a single optical fiber, and further a single laser may produce multiple
wavelengths. Embodiments
of the present invention contemplate and include these laser system
configurations. In
embodiments of the present invention, an interchangeable and disposable tip
104 is coupled to the
treatment end of the handpiece 102. Embodiments of the tips in the present
invention typically
have an outer shell or skin formed from bio-safe plastics or metals, and may
be hermetically sealed.
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[0034] FIG. 2 illustrates in greater detail the laser treatment systems
depicted in FIG. 1 above.
FIG. 2 shows controlled tissue treatment system 100 in accordance with aspects
of the present
invention. In accordance with the example shown in FIG. 2, system 100
comprises power source
110 that energizes light emitter 120 for emission of a light beam via an
electrical or optical
connection 115; optical fiber 130 for transmission of the light beam; movable
handpiece 140 with
an interchangeable tip (not shown in detail here) and with an optical element
160 coupled to optical
fiber 130 for emission of the light beam towards target area 150; detector 170
for detecting
variations in positional parameters of handpiece 140; and controller 200 for
controlling operational
parameters of the light beam emitted towards target area 150 in response to
the detected variations
in the handpiece positional parameters. Light is typically passed through an
optically transparent
window 155 that may be flat or cuived in one or more aspects. Optical element
160, detector 170,
and window 155, in whole or in part, may be coupled to andlor enclosed within
an interchangeable
tip according to embodiments of the present invention. The connection 115 may
consist of simply
a free-space region through which an optical beam is passed. Controller 200
may comprise
processor 202 for calculating new operational parameters and interface unit
210 for selecting and
adjusting operational parameters of apparatus 200. The controller 200 may
control operational
parameters by adjusting parameters in at least one of the following: power
source 110, light emitter
120, and optical element 160. For clarity, only one of these configurations is
illustrated.
[0035] Light emitter 120 of treatment system 100 may be any optical power
source. Light emitter
120 may be implemented, at least in part, using one or more light power
sources. For certain
applications, light emitter 120 may desirably include multiple light power
sources arranged in an
array, such as a one-dimensional array or ttuo-dimensional array. It is
prefeiTed that the light power
source utilized in the present invention is a laser, although other non-laser
optical sources may be
used. Suitable lasers according to the invention may include noble gas lasers
(e.g., argon lasers,
helium-neon lasers, etc.), diode lasers, fiber lasers, and tunable lasers.
However, it must be
understood that the selection of a particular laser for the tissue treatment
system 100 is dependent
on the type of the deimatological treatment selected for a particular
application. Light emitter 120
is typically adapted to produce optical power between about 1 W and about
100W, preferably about
30W.
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100361 Light emitter 120 emits one or more optical beams having one or more
wavelengths. In
laser-induced tissue treatment, each optical beam may be characterized by a
particular set of optical
operational parameters that are selected to produce a desired dermatological
effect on target area
150. Operational parameters of the light beam may include optical fluence,
power, pulsation rate,
duty cycle, light intensity, timing of pulse initiation, pulse duration, and
wavelength.
[0037] In some embodiments, light emitter 120 is preferably capable of
generating light at
wavelengths with high absorption in water. Cellular water absorbs light energy
and transfoi-nis the
light energy into heat. Preferably, wavelengths larger than 190 nm, such as
wavelengths in the
range from 190 nm to 10600 nm, preferably from 700 nm to 1600 nm, and most
preferably about
1550 nni are used in the apparatus 200. Desirably, light emitter 120 is an
erbium-based fiber laser
designed for about 1550 nm range operation. Light emitter 120 may be capable
of providing one
wavelengtli or a range of wavelengths or may be tunable across a range of
wavelengths. One or
more light emitters 120 may be powered by power source 110 to produce a
variety of different
wavelengths or wavelength ranges used in dermatological treatment. Light
emitter 120 may be
adapted to selectively produce pulses of laser light at a frequency of between
0 to about 50,000
pulses per second and preferably 0 to about 1,000 pulses per second.
Preferably, light emitter 120
emits a beam having pulse energy per treatment spot of about 1mJ to about
1000mJ, more
preferably between about lOmJ and about 30 mJ, each pulse having a pulse
duration per treatment
spot between about 0.1 ms and about 30ms, more preferably about 1 ms.
[0038] In some embodiments, power source 110 and light emitter 120 are
typically used, for
example, for non-ablative coagulation of an epideimal and/or a dermal layer of
the target area 150.
Typically, for this puipose, an optical fluence incident to target tissue area
150 greater than about 5
J/cm'', such as an optical fluence in the range from about 10 J/cm 2 to about
1000 J/cmz, is adequate
for coagulating tissue. Generally, the optical fluence is adapted to the
wavelength and the tissue to
be treated. If various dennatological effects are desired, the power source
110 and light emitter 120
may be selected with the capacity to produce optical operational parameters
suitable for other types
of tissue treatment. For example, if ablation of an epidermal layer of the
target area 150 is desired,
the power source 110 and the light emitter 120 may be used with the capability
to emit a liglit beam
with a wavelength of about 2940 nm and optical fluence higher than 10 J/cm2.
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[0039] Optical fiber 130 may be any optical apparatus suitable for
transmission of light emitted
from light emitter 120. Fiber 130 may be constructed of a material that allows
for free
manipulation of the handpiece 140 and for repeated bending in order to direct
the light beam from
emitter 120 to various portions of target area 150. Fiber 130 may have beam-
inlet end 132 that is
aligned with the light beam emitted from light emitter 120 so that the light
beam is coupled into
optical fiber 130, and beam-outlet end 134 for emission of the transmitted
light beam to handpiece
140. More than one fiber may be used to transmit the light beam from emitter
120 to handpiece
140. Alternatively, other optical delivery mechanisms 130, e.g., mirrors or
waveguides may be
used to guide the light beam from the light emitter 120 to the proximal end of
handpiece 140.
[00401 Refei-ring to FIG. 3, like elements have similar reference numerals to
those for FIG. 2. The
housing 142 of handpiece 140 is a unit adapted for convenient holding by a
human hand during the
delivery of dei-matological treatment. Shape of housing 142 of the handpiece
140 provides for a
wide range of motion to manipulate the handpiece during treatment. Housing 142
may be made out
of a light plastic, such as Kydex and may hold optics and electronics used for
dermatological tissue
treatment. Housing 142 may be connected to fibers 130 near the beam-outlet
ends 134 and may
contain a sti-ucture that allows the light beam to be guided tlu=ough housing
142 and to be emitted
from a tip (not shown in detail here) attached to the distal end of the
housing, so that the light beam
can propagate towards target area 150. For the most efficient treatment, it is
preferred to direct and
point the light beam emitted from output 148 at a substantially right angle to
tissue 150.
[0041] Handpiece 140 may further include optical element 160 that is optically
coupled to fibers
130. Optical element 160 directs optical energy from fibers 130 to target
tissue area 150. In some
embodiments, optical element 160 directs optical energy to target area 150 by
focusing or
collimating the light beams emitted from fibers 130 to one or more treatment
zones within target
area 150. Optical element(s) 160 may be implemented using one or more optical
elements, such as
mirrors, optical lenses, optical windows, rotating elements, counter-rotating
wheel elements,
electro-optic elements, acousto-optic elements, etc. Typically, for non-
ablative treatment, the
swath width of target area 150 is pre-selected at about 0.5 cm to about 2.0
cm.
[0042] Optical element(s) 160 may be configured to allow for control of the
microscopic treatment
patterns and density of the treatment zones. As will be discussed in greater
detail below,
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substantially uniform pre-selected pattein and density of the treatment zones
across the entire
treated tissue area may be achieved by controlling optical element 160.
[0043] Handpiece 140 may further comprise deflector 146 or scanner mechanism.
Deflector 146
may be an optical component suitable for deflecting the light beam of the
wavelength pre-selected
for the treatment, such as mirrors, prisms, grids, diffractive optical
elements, holographic elements,
rotating elements, etc. Deflector 146 may be operationally coupled to optical
element 160 to
modify the light beam emitted from optical element 160. Preferably, deflector
146 is movably
mounted within housing 142 for displacement by actuator 145 in response to a
controlling signal.
Actuator 145 may be a piezoelectric, galvanometer, rotating element, etc., and
operates to adjust the
position of deflector 146 to a position corresponding to the desired treatment
intensity and pattern.
Actuator 145 may be controlled in real-time by controller 200 to modify the
light beam so that the
microscopic treatment is delivered from handpiece 140 in a uniform or non-
unifoim pattern across
target area 150. Altemately, handpiece 140 may not include a deflector 146. In
some
embodiments, deflectors, scanners and actuators may be outside of the
handpiece (e.g., in the
console). Beam outlet end 134 may enter from the top.
[0044] Referring to FIGS. 2- 4, handpiece 140 advantageously includes detector
170 for detecting
variations in the positional parameters of handpiece 140. Like elements in
FIGS. 2 - 4 have similar
reference numerals. Detector 170 may comprise an image acquiring sensor 180
for repeatedly
capturing images of target area 150 and image processing device 190 for
analyzing in real-time
vaiying positional parameters of the moving handpiece 140. Sensor 180 may be
an optical
navigation device that allows quantitative measurement of the movement of
handpiece 140. The
basic operating principle of the optical navigation teclulique is shown in
FIG. 4. Light-emitting
diode 182 illuminates the surface of the tissue underneath handpiece 140. The
light may be
converged by means of converging lens 184 on the treated surface to be
reflected off the
microscopic textural features in the target area 150. The converged beam of
light scattered from
the surface is then refocused by converging lens 186 to foim an image on
position sensor 180.
Sensor 180 continuously takes pictures of the points in the treated area at
high speed as handpiece
140 moves. The image capturing speed of sensor 180 is sufficiently high to
allow sequential
pictures to overlap. Sequential images from the sensor 180 are sent to image
processing device
190. The optical path of sensor 180 between the target area and the converging
lens 186 may
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include an optically transparent window 155. Image processing device 190 may
be a
programmable digital computer that uses optical navigation engine for
analyzing the sequential
images captured by sensor 180.
[0045] Possible outcomes from controller 200 can include triggering an
"operation" mode and a
"stop" mode. In the "operation" mode, the treatment continues, as will be
discussed in greater
detail below, and the operational parameters of the treatment system 100 are
monitored in real-time
in response to the signals indicative of the changes in the handpiece
positional parameters and/or in
response to signals from the tip. In the "stop" mode, controller 200
immediately halts all
operations of system 100 in response to detecting that a tip usage parameter
has been exceeded or a
significant change in treatment conditions that render the continuation of
treatment unsafe or
ineffective. Specifically, treatment with a dosage level that exceeds a lower
tlu=eshold for tip usage,
for example, but is below the upper threshold is considered acceptable.
Treatment at a dosage level
that exceeds the upper threshold or is below the lower threshold level may
require shutdown of
treatment system 100.
[0046] A specific example of detector 170 usable in the treatment system 100
is an optical
navigation sensor produced by Agilent Technologies, Inc., of Palo Alto,
California, and particularly
the ADNS 2600 series optical navigation engine. The optical navigation engine
(i.e. image
processing device 190) produces measurements of changes in the handpiece
position by optically
acquiring sequential surface images up to about 1500 times per second and
mathematically
determining the direction and magnitude of the handpiece movement at the
maximum of 400
counts per inch (cpi) and at speeds up to 12 inches per second (ips).
[0047] If an optical navigation sensor such as described in the previous
paragraph is used for
detector 170, then in some cases this detector can be made more robust by the
addition of contrast-
enhancing substances, such as particles, dyes, solutions, colloids or
suspensions to the target area
150 to enhance the contrast for the optical navigation sensor. One example of
contrast enhancing
particles would be ink particles that are spread onto the skin by painting or
marking the skin prior
to treatment with the handpiece. Food dyes may alternately be used for
contrast enhancement.
Often the contrast-enhancing substance is chosen as an absorber or a reflector
of the LED light
(e.g., a blue dye may be chosen for use with a red LED).
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[0048] Retuining to FIG. 2, treatment system 100 advantageously includes
controller 200 for
adjusting in real-time the range of operational parameters of the light beam
in response to detected
variations in the handpiece positional parameters and/or tip usage and tip
parameter information.
Controller 200 may be a general puipose prograinmable digital computer
connected to detector 170
and/or tip memory (not shown) to receive a precise digital output. Controller
200 can be
programnied to sample in real-time variations in the handpiece positional
parameters, tip usage, tip
sensor readings, and/or tip parameter information; to display the positional
parameters
measurements on the display monitor (not shown); to store the measurements; to
apply treatment
criteria logic to the measured signals and tip infoimation for detei-mining
necessaiy adjustments in
operational parameters, and to implement adjustments to at least one
operational parameter while
the treatment continues. Possible criteria for treatment logic may include
changes in the position or
the velocity of the handpiece relative to the target area 150, changes in
angle of the handpiece
relative to the target area 150, changes in the distance of the handpiece
fi=om the target area 150, tip
usage limits, tip sensor readings, system operational limits imposed by tip
type, tip treatment
parameter limits and/or tip usage, or combinations thereof. In some
embodiments, separate
controllers and processors may be used to control and communicate with the tip
and the positional
controls for the treatment system.
[0049] Controller 200 may comprise interface unit 210 for receiving and
processing signals
indicative of the variations in the positional parameters from detector 170
and/or tip information
and sensor readings, analyzing the signals, sending signals requesting
deteimination of suitable
operational parameters; and performing adjustments to the signals indicative
of operational
parameters. Interface unit 210 may include analog processing circuitry (not
shown) for
normalization or amplification of the signals from detector 170 and an analog
to digital converter
(not shown) for conversion analog signals to digital signals. Interface unit
210 may be operably
coupled to the components of system 100, i.e., power source 110, light emitter
120, actuator 145,
tip memory, tip sensors, and tip security chip for selecting initial
operational parameters for the
tissue treatment and for controllably adjusting in real-time components of the
treatment system 100
to generate new suitable operational parameters.
[0050] Controller 200 may further include processor 202 for determining a set
of desired
operational parameters in response to the signals from interface unit 210
indicative of the changes
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in tip usage or treatment dosage, as well as in response to information on tip
type, tip operational
parameters, etc. Processor 202 may be embodied as a microprocessor, an ASIC,
DSP, or other
processing means that are suitable for determining the desired operational
parameters. Upon
receiving the signals from interface 110, processor 202 determines a new set
of suitable operational
parameters. Examples of operational parameters for the light emitter 120 are
optical power, pulse
repetition rate, pulse energy, pulse duty cycle, and wavelength. Examples of
other operational
parameters are handpiece temperature, actuator 145 movement rate, and actuator
145 movement
pattern. Processor 202 may include computational means (not shown) for
calculating specific
operational parameters, or may be based on neural networks and fuzzy logic
techniques for
systeniatically arriving at optimal operational parameters for the desired
treatment using the
software of this invention. Alternatively, the computational means may
comprise a memory look-
up tables for generating operational parameters values for a pre-selected
treatment given the
measured positional parameters, the treatment dosage, tip usage, etc. Memoiy
look-up tables
would provide coherent data sets of signal values from detector 170 and
wiTesponding values of
desirable operational parameters. Thus, the software of the invention
associated with controller 200
allows processor 202 to perform in real-time mapping of operational parameters
of treatment
system 100 as a function of the handpiece positional parameters, tip data and
to output the set of the
desired operational parameters to interface unit 110.
[0051] Embodiments of the present invention include interchangeable tips on
the treatment end of
the handpiece. Such tips typically include one or more optical elements 160,
LED(s) 182 and
window(s) 155. However, various sets of these elements may be included or
excluded from the tip.
The elements shown in FIGS. 2 - 4 that are not included in a tip are typically
included in the
handpiece. Alternate embodiments may include multiple LEDs producing either
the same or
different wavelengths. Alternate embodiments may further include multiple
windows 155 or no
windows. In the latter case, an open aperture may replace the window 155.
[0052] FIG. 5 shows an embodiment of the present invention in which the distal
end 530 (i.e.,
treatment end) of a handpiece 502 is coupled to the proximal end 532 of a tip
504. Handpiece 502
includes one or more electrical connections (e.g., 520, 522) to tip 504. The
electrical connection(s)
at the interface between tip 504 and handpiece 502 are not permanent, but
rather are configured so
that when tip 504 is mechanically attached to handpiece 502 the electrical
connections are reliably
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created and maintained during use and treatment. For example, contact pads,
spring contacts, pogo
pins, ball contacts and the like may be used for electrical contacts (520,
522), Tip 504 is configured
to have electrical contacts to match those of the handpiece, although tip 504
may have more or less
electrical contacts than a given handpiece. The electrical connections create
a communications path
between tip 504 and handpiece 502. Handpiece 502 typically has a light energy
pathway 506,
including, for example, one or more optical fibers, lenses, reflective
elements, or diffractive or
holographic elements. The light energy pathway in tip 504 may include optics
to receive and
transmit light energy from the handpiece to a target area of tissue to be
treated. Tip 504 may
include an apei-ture 528 through which optical energy froin the handpiece
passes. In the example
shown in FIG. 5, aperture 528 is an open aperture.
[0053] Tip 504 typically includes a memory 512 that is attached, either
directly or indirectly, to tip
504. Memory 512 may be an EPROM or EEPROM, for example. Memory 512 may be part
of a
security chip, a control chip, or a microprocessor. Alternately, memoiy 512
may be a separate and
stand alone memory element. For the purposes of this application, a processor
may be, for
example, a security chip, a control chip, or a microprocessor. Memory 512 is
typically connected
via one or more wires 518 to an electrical contact to the handpiece 502 in
order to communicate
with the handpiece 502 and/or a console or system (not shown). Memory 512 may
serve various
purposes, including tip-system security. Tip-system security typically
consists of the memory
holding a secure and often enciypted code (e.g., a hash algorithm, for
exaniple a 128-bit Secure
Hash Algorithm-1 (SHA-1) codes) for use in authenticating the tip to the
handpiece and/or
treatment system. Typically, the handpiece and/or treatment system includes a
controller and a
memory holding a similar or matching code to that stored in the tip memory
512. One or more
encryption algorithms, handshake protocols and authentication procedures may
be used to ensure
that an appropriate and specified tip is used with the system. For example, a
Dallas Semiconductor
DS2432 1k-Bit Protected 1-WireTM EEPROM (manufactured by Dallas Semiconductor
of
Sunnyvale, California) may be used for such secure and encrypted memory. In
this example, a
single wire may be used between the memory 512 and the system controller and
communication
may be completed by a 1-wire protocol (e.g., 1-wire SHA-1 protocols).
[0054] In one embodiment, the system uses a challenge-response protocol, a
keyed hash algorithm,
and a secret key to authenticate the tip. The host generates a challenge, such
as a random number.
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The challenge is electronically communicated to the tip. The tip and the host
separately
concatenate the challenge with their secret keys and generate a hash of that
string. The tip sends
the hash that it generated back to the host as the response to the challenge.
The host compares the
response from the tip to the hash that the host created fi=om the challenge.
If the two hashes match,
then the two secret keys must be identical and the tip is known to be
authentic, which enables
delivery of light energy to the treatment area. If authentication is not
successful, then deliveiy of
light energy to the tip and the treatment area is prevented.
[0055] Examples of hash algorithms are MD5, MD4, and SHA1. Those skilled in
the ai-t will be
able to substitute other hash algorithms. The secret key may be coded into
software, stored in
memory, or written into a non-readable memory for use by a specialized
encryption chip
implementing the above protocol. One example of a non-readable memory is sold
by Dallas
Semiconductor, for example, model numbers ds1963 and ds2432. The method of
communication
between the tip and the host may be any form of communication, such as the 1-
wire protocol, an
RF data link, or ethernet.
[0056] In some embodiments of the present invention, tip memoiy 512 plays a
role in tip usage
monitoring and control. In such embodiments, tip memory 512 stores data about
tip usage. Such
tip usage data may include one or more of the following: number of energy
pulses transmitted
through the tip; number of pulses emitted by one or niore attached light
sources; accumulated
energy or fluence transmitted through the tip; accumulated energy or fluence
emitted by one or
more attached light sources; number of treatment zones or spots transmitted to
the tissue being
treated; area of tissue treated using the tip; power transmitted through the
tip and/or transmitted by
the one or more attached light sources. A usage limit based on any of the
above-listed categories of
tip usage data may be stored in tip memory such that when the usage limit is
exceeded, the tip
and/or the system cease to function in part or in whole. Additionally, other
tip usage parameters
gathered during treatment with the tip attached may be stored in the memory,
such as, for example:
pulse repetition rate; wavelength(s); number of sources used; temperature of
the tip, handpiece
and/or system; nuniber of patients treated; types of treatment regimens used
(for example, multiple
pass treatments or single pass treatments); etc. These other tip usage
parameters may be useful in
determining tip life and/or for adjusting treatment parameters over the life
of the tip, for example.
If the tip is removed from a system and later coupled to the same or a
different system, these saved
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parameters may be useful in monitoring total tip life and/or in setting
appropriate treatment
parameters taking into account the history of the tip. The handpiece or system
to which a tip is
attached can access the memory 512 through one or more electrical contacts. A
controller or
microprocessor in the handpiece or console may read from and/or write to the
memory via single or
multiple electrical or optical connections using various conimunication
protocols.
[0057] Alternate embodiments may include storing in tip memory a code that
unlocks a memory in
the treatment system. The unlocked poi-tion of treatment system memoiy may
store information
regarding the specific tip-system combination. For example, a tip may store a
code relating to a
patient or a prior treatment. When such tip is attached to the treatment
system and the tip memory
is read, the code in tip memoiy unlocks a section of system memory and patient
inforniation or
pr-ior treatment parameters are retrieved for use in the cun=ent treatment.
[0058] In further embodiments of the present invention, tip memoiy 512 stores
tip configuration
infoimation, such as, for exanlple: tip width (e.g., tip treatment zone width
and/or length); tip focal
properties, such as focal length (in air or in tissue) and spot size
(typically measured at the tissue
surface); tip shape; tip parameter limits; tip treatment parameters; and so
forth. Tip shape may
include, for example, cross-sectional (i.e. at the treatment end of the tip in
a plane perpendicular to
the optical axis of the treatment beam and/or parallel to the tissue surface)
shapes (e.g., round, oval,
polygonal, synunetrical or asymnletrical) or profile (i.e. looking at the tip
in a direction
substantially perpendicular to the optical axis of a treatment beam
transmitted through the tip)
shapes typically on the treatment facing side(s) of the tip (e.g., flat faced,
rounded, polygonal,
indented, bumped, etc.).
[0059] Tip shape may also be designed to fit particular anatomical areas, such
as for example,
small or difficult to reach areas around an eye or a nose. Tip parameter
limits may define system
parameters within which the tip may safely and/or effectively be used. Such
parameter limits may
include, for example: energy limits, wavelength(s), pulse repetition rates,
power, temperature
limits, contacting versus non-contacting treatments, accumulated time of
treatment, and so forth.
Tip treatment parameters may define treatment paranieters to be used when
employing a particular
tip. For example, tip treatment parameters may include data requiring that a
tip be used only
around eyes or noses, for exainple, or that such a tip is particularly suited
for treating a specific
disease or tissue condition, such as, for example, pigmented lesions or acne.
Alternately, tip
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treatment parameters may indicate that a particular dye or contrast agent be
used to enhance the
sensing response from an LED within the tip.
[0060] A controller or microprocessor in the handpiece and/or in a system
console reads the tip
configuration infoimation, tip usage information, tip usage parameters and/or
other system
information from the tip memory and uses software and/or finnware algorithnis
to create one or
more control signal(s) to alter the operation and/or configuration of the
system and/or handpiece.
Fui-ther, the controller and/or microprocessor may cause signals to be sent to
an interface unit to
provide infoimation to a user. The user can then make treatment decisions or
alter the system
parameters based thereon, for example, through a touch screen, a keyboard, a
mouse or other input
mechanism. For example, a tip may store information indicating that it is to
be used only for
treatments around the eyes, at wavelengths between about 1400 nm and about
1600 nm and at
energies less than about 10 mJ. A controller or microprocessor reading this
information may send
control signals to one or more lasers to produce wavelengths in the range of
1400-1600 nm and
with energies no greater than 10 mJ. A user may be notified via an interface
unit, such as a
monitor, that the tip is primarily for use around eyes, but the user may be
offered the option to
manually change treatment parameters such as the wavelength and/or energy,
among others.
[0061] Tip 504 typically includes an LED 514. LED 514 is typically used to
illuminate a treatment
surface, for example, for targeting purposes or to assist in sensing movement
or location of the
handpiece relative to the tissue. LED 514 may be coupled via a wire 516 to an
electrical connector
520 in order to receive power and/or control signals from the handpiece 502 or
a system coupled to
the handpiece. Alternately, LED 514 may be attached to a batteiy within the
tip. A given tip 504
may include multiple LEDs. Typically, LED 514 is mounted in tip 504 in an
orientation allowing a
portion of the light emitted by the LED to pass through an LED apei-ture 526.
In alternate
embodiments, LED light may pass through the same aperture as the treatment
beam (i.e. aperture
528).
[0062] Tip 504 includes a connector mechanism for attaching the tip to a
handpiece 502. The
proximal end 532 of tip 504 includes a connector mechanism configured to hold
the tip in place
against the distal end 530 of a handpiece 502 with sufficient force to
maintain an electrical contact
and an optical coupling between the tip and the handpiece, especially while
the handpiece is moved
across tissue during treatment. The connector nlechanism may take various
forms. In the example
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of FIG. 5, a magnetic connector 524 is shown. Magnets may be placed on one or
both sides of the
interface between tip 504 and handpiece 502. Alternate attachment mechanisms
may include, for
example: a clip; a screw; a screw-on connection (i.e. the tip and the
handpiece have corresponding
male and female threaded portions); an adhesive; a bayonet-style connector; a
snap and/or a latch.
Additionally, tip 504 is shaped so that it can be removably attached to the
distal end 530 of
handpiece 502. Dowels and coiresponding holes may be used to seat and hold the
tip against the
handpiece. Further, the shape of the tip may be configured to fit the
handpiece tightly. For
example, the tip shape may be more confornial to match the shape of the distal
end of the
handpiece, rather than being a flat surface that butts flush against a flat
surface of the handpiece.
[0063] Tip 504 may further include one or more sensors (not shown) for
monitoring various
parameters of the tip, treatment beam and/or the tissue being treated. For
example, a monitor
photodiode may be included in the tip to monitor the treatment beam. This may
require a partially
reflective element to monitor a portion of the treatment beam. This real-time
monitoring of
treatnient beam characteristics may be used to alter the system and/or
treatment parameters. As a
further example, a temperature sensor, such as, for example, a thermocouple
may be coupled to the
tip. In some embodiments a thermocouple is attached to the tip at or near the
treatment end of the
tip, so as to monitor tissue surface temperature. Such sensors are typically
in communication with
the treatment system, either electrically, optically or by wireless
connection. Fui-ther, some
embodiments may include radio-frequency identification (RF ID) chips as a
further security
measure (i.e. if a RF ID communication system is included in the system to
check the RF ID on the
tip) and for tracking puiposes to identify individual chips and their
locations. Such RF ID chips
may store some of the data and codes described above as stored in the tip
memory.
[0064] FIG. 6 is an alternate embodiment of the present invention. FIG. 6 is
similar to FIG. 5 in
that the same handpiece components and handpiece configuration are depicted in
FIG. 6. As such,
in FIG. 6 like elements are numbered similarly to those in FIG. 5. Tip 604
differs from tip 504 in
FIG. 5 at least in that tip 604 has a different connector mechanism (i.e. it
does not show a magnet)
and tip 604 has window(s) 626, 624 and an aperture 628. The memory 612, LED
614, and
electrical connections 616, 618 are similar to corresponding parts in FIG. 5
and serve similar
functions.
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[0065] Window 624 is a window through which light emitted by LED 614 is
transmitted. Window
626 is a treatment window through which light emitted from the system (i.e.
from handpiece 502) is
transnlitted to a tissue surface. Window 624 and treatment window 626 may be a
single window in
some embodiments. Windo Js 624 and 626 are typically made of glass, sapphire,
diamond, quartz
or silica, although other substances may be chosen for their optical and/or
theimal properties. In
some embodiments, windows 624 and/or 626 may include filters for limiting the
transmission of
one or more wavelengths. For example, in systems having multiple lasers or
light sources emitting
multiple wavelengths, a tip may be chosen to transmit or block one or more
wavelengths depending
on the desired treatment parameters. Such filters may include thin film
filters, reflectors and/or
coatings in single-layer or multi-layer configurations. Such filters may be
absorptive or reflective
or a combination thereof. Such filters inay include doped glass filters, fused
silica with a dielectric
coating, silicon, etc. Alternately, window 626 may include diffractive,
holographic, polarizing
elements, opto-electronic elements, acousto-optic elements, a lens, an optical
limiter, a saturable
absorber, or a passive q-switch element to alter the light transmitted
tlu=ough the window andlor to
alter the treatment pattern and spot dimensions on the tissue.
[0066] Aperture 628 is optional. Aperture 628 may be used to limit the
nuinerical aperture of the
system and/or to limit the size of the treatment pattern at the tissue. For
example, if the handpiece
produces a set number of spots (e.g. 30 across a single line peipendicular to
the direction of
movement of the handpiece) in a given treatment pattern to create a set
treatinent zone dimension
(i.e. 15 mni wide), then apei-ture 628 may be used with a smaller dimensioned
tip to limit the
treatment to fewer spots and a narrower treatment zone (e.g., 15 spots across
an 8-mm-wide line).
Apei-ture 628 may include a reflective coating to direct light incident
thereon in a desired direction,
such as, for example, to a beam dump or an absorbing heat sink. Alternately,
aperture 628 may be
a heat sink or an absorber.
100671 FIG. 7 shows an example of the various tip 704 dimensions that may be
changed between
individual tips that are interchangeable with the same handpiece 702. A set of
two or more tips are
configured to fit and be attached to a given handpiece. Each individual tip in
the set is different in
at least one aspect from the other individual tips in the set. The differences
between tips may
include differences in: dimensions; shapes; windows; filters; memory
configurations or sizes;
number and type of LED(s); aperture(s); additional connector mechanisms;
number and type of
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electrical connections; additional sensors; security codes, operational
parameters and/or other
information stored in tip memory; and so forth. FIG. 7 shows some of the
dimensions that may be
different between individual tips in a set of tips. For example, the width 706
may be different from
one tip to the next. Additionally, window width(s) 712 and/or 710 may be
different from one tip to
the next. Altering treatment window width 710 may also impact the aperture of
tip for treatment
purposes. The length 708 may also be different from one tip to the next.
Length 708 will typically
alter the focal depth of a treatnient beam relative to the treatment window
726 and the surface of
tissue being treated, as well as the spot size of the treatment beam at the
tissue surface.
100681 FIGS. 8a and 8b illustrate the effects of altering a length dimension
for two tips (804 and
806) each attached separately at different times to the same treatment system
and handpiece 802.
In FIGS. 8a and 8b, like elements are referenced with like reference numerals.
A handpiece (e.g.,
in the absence of a tip) produces a treatment beam having a set focal length
824, numerical aperture
and beam profile (i.e. light energy beam 808). Tip 804 has a different length
820 fi=om the length
822 of tip 806. This difference in tip length will alter the depth in the
tissue (i.e. depth 812 for tip
804 vs. depth 814 for tip 806) at which the beam will focus (i.e. the beam
waist) and will also
impact the spot size at the tissue surface (i.e. spot 816 for tip 804 vs. spot
818 for tip 806). Altering
spot size, spot shape and/or focal depth from one tip to another significantly
impacts the treatment
parameters and typically the tissue response. For example, a larger spot size
may cause a larger
treatment zone lesion, and a deeper focal point may cause a deeper treatment
zone lesion and/or
necrotic zone. Further, altering these treatment dimensions may alter the
shape and size of the
treatment zone.
100691 The foregoing describes a system and method for laser surgeiy wherein a
focused optical
signal such as a laser, LED, or an incoherent source of optical energy is
advantageously created to
achieve treatment zones using interchangeable tips. Persons of ordinary skill
in the art may modify
the particular embodiments described herein without undue experimentation or
without departing
from the spirit or scope of the present invention. All such departures or
deviations should be
construed to be within the scope of the following claims.
23
